Finish to use on outdoor SPF bench?

So it’s probably not the best option of wood, but I am making a “coopers bench” for my bow building. The problem I have is that I don’t have anywhere indoors at the moment to put it. It won’t even have a roof to block the rain. (a quick Google for coopers bench will show you what it is if not sure)

Now, I’m using plain SPF lumber from Home Depot. I do not expect this bench to last very long, It’s more of a prototype. I’d like it to be bale to last a couple years if possible, but I don’t have a lot of experience with woodworking and especially with prepping stuff for outdoors. Mostly just whittling and I built an English longbow. Gotta start somewhere :)

Anyways, I don’t know what to finish this bench with, not even sure if this thing lasting a couple years is realistic. I will definitely be staining it, already picked out a Minwax stain I’ll be using. As for the finish I don’t really know. I’ve heard of Epifanes varnish being used on outdoor benches and working well.

Any suggestions at all would helpful. Does it matter how many coats of stain I should put on? If anyone suggests anything, could you also suggest how to apply it? eg. stain it, varnish, sand it after x amount of time, varnish again, how many coats etc.